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The present study explores tissue and cellular distribution of ectonucleoside triphosphate diphosphohydrolase 2 (NTPDase2) and the gene and protein expression in rat spinal cord during the course of experimental autoimmune encephalomyelitis (EAE). Given that NTPDase2 hydrolyzes ATP with a transient accumulation of ADP, the expression of ADP-sensitive P2 purinoceptors was analyzed as well. The autoimmune disease was actively induced in Dark Agouti female rats and the changes were analyzed 10, 15 and 29 days after the induction. These selected time points correspond to the onset ( Eo ), peak ( Ep ) and recovery ( Er ) from EAE. In control animals, NTPDase2 was confined in the white matter, in most of the glial fibrillary acidic protein (GFAP)-immunoreactive (ir) astrocytes and in a considerable number of nestin-ir cells, while the other cell types were immunonegative. Immunoreactivity corresponding to NTPDase2 decreased significantly at Eo and Ep and then returned to the baseline levels at Er . The preservation of the proportion of GFAP single-labeled and GFAP/NTPDase2 double-labeled elements along the course of EAE indicated that changes in NTPDase2-ir occurred at fibrous astrocytes that typically express NTPDase2 in normal conditions. Significant downregulation of P2Y1 and P2Y12 receptor proteins at Eo and several-fold induction of P2Y12 and P2Y13 receptor proteins at Ep and/or Er were observed implying that the pathophysiological process in EAE may be linked to ADP signaling. Cell-surface expression of NTPDase2, NTPDase1/CD39 and ecto-5'-nucleotidase (eN/CD73) was analyzed in CD4+ T cells of a draining lymph node by fluorescence-activated cell sorting. The induction of EAE was associated with a transient decrease in a number of CD4+ NTPDase2+ T cells in a draining lymph node, whereas the recovery was characterized by an increase in NTPDase2+ cells in both CD4+ and CD4- cell populations. The opposite was found for NTPDase1/CD39+ and eN/CD73+ cells, which slightly increased in number with progression of the disease, particularly in CD4- cells, and then decreased in the recovery. Finally, CD4+ NTPDase2+ cells were never observed in the spinal cord parenchyma. Taken together, our results suggest that the process of neuroinflammation in EAE may be associated with altered ADP signaling.

Se trata de una tesis doctoral presentada en la modalidad compendio de publicaciones. En ella, se presenta una línea de trabajo de investigación mediante la presentación sucesiva de tres artículos ya publicados en diferentes revistas de impacto en el ámbito de las enfermedades infecciosas. Los trabajos presentados en esta tesis nacen de una necesidad clínica patente en nuestra asistencia a los pacientes con infección por VIH, ya que el uso clínico de maraviroc, un antagonista del correceptor de quimiocinas CCR5, se veía dificultado por la necesidad de conocer el tropismo vírico y los métodos disponibles para ello eran caros, complejos y con problemas de interpretación. Por ello, el primer trabajo de la presente tesis fue diseñar una herramienta clínica más sencilla rápida y barata que los métodos disponibles hasta entonces; además, esta herramienta clasificaba al paciente en sensible al fámaco o no, más allá de un resultado categórico de tropismo. Este objetivo se abordó en el primer artículo publicado en "Journal of Antimicrobial Chemotherapy" en 2009. Posteriormente, realizamos un análisis de comparación entre nuestra herramienta clínica y el método fenotípico estándar de oro para determinar el tropismo vírico, con el onjetivo de alertar sobre las implicaciones clínicas que podrían tener tasas de discrepancia entre ambos métodos superiores al 15%. Este segundo objetivo se en el segundo artículo publicado en "Antiviral Research" en 2011. Por último, nos interesaba conocer cuál era la eficacia y seguridad de maraviroc asociado a diferentes antirretrovirales en nuestra cohorte de pacientes, masivamente coinfectada por virus de la hepatitis C, y en diferentes escenarios clínicos. Además, en la mayoría de estos pacientes se decidió iniciar tratamiento con maraviroc a través de la herramienta clínica previamente diseñada. Este tercer objetivo se abordó en el último trabajo publicado en "Current HIV Research" en 2010. Los resultados obtenidos en estos tres trabajos permiten extraer las siguientes conclusiones: 1. Una herramienta clínica que permite determinar la sensibilidad clínica a maraviroc es un método sencillo y eficaz para considerar a un paciente candidato a recibir tratamiento con maraviroc. 2. Se observan tasas de discrepancia entre esta herramienta clínica y los métodos fenotípicos superiores al 15%, lo que puede tener importantes repercusiones clínicas. 3. Un régimen antirretroviral con maraviroc es eficaz y seguro en diferentes escenarios clínicos, asociado a diferentes antirretrovirales y en una población con elevada tasa de coinfección por virus de la hepatitis C. Premio Extraordinario de Doctorado US

Estrogen receptor (ER)-negative tumors represent 20-30% of all breast cancers, with a higher proportion occurring in younger women and women of African ancestry. The etiology and clinical behavior of ER-negative tumors are different from those of tumors expressing ER (ER positive), including differences in genetic predisposition. To identify susceptibility loci specific to ER-negative disease, we combined in a metaanalysis 3 genome-wide association studies of 4,193 ER-negative breast cancer cases and 35,194 controls with a series of 40 follow-up studies (6,514 cases and 41,455 controls), genotyped using a custom Illumina array, iCOGS, developed by the Collaborative Oncological Gene-environment Study (COGS). SNPs at four loci, 1q32.1 (MDM4, P= 2.1 x 10(-12) and LGR6, P = 1.4 x 10(-8)), 2p24.1 (P = 4.6 x 10(-8)) and 16q12.2 (FTO, P = 4.0 x 10(-8)), were associated with ER-negative but not ER-positive breast cancer (P> 0.05). These findings provide further evidence for distinct etiological pathways associated with invasive ER-positive and ER-negative breast cancers.

Abstract Background The COVID-19 pandemic and pandemic response created novel challenges for abortion services. Canada was uniquely positioned to transition to telemedicine because internationally common restrictions on abortion medication were removed before the pandemic. Objective We sought to characterize the experiences of abortion health care professionals in Canada during the COVID-19 pandemic and the impact of the pandemic response on abortion services. Methods We conducted a sequential mixed methods study between July 2020 and January 2021. We invited physicians, nurse practitioners and administrators to participate in a cross-sectional survey containing an open-ended question about the impact of the pandemic response on abortion care. We employed an inductive codebook thematic analysis, which informed the development of a second, primarily quantitative survey. Results Our initial survey had 307 respondents and our second had 78. Fifty-three percent were family physicians. Our first survey found respondents considered abortion access essential. We identified three key topicss: access to abortion care was often maintained despite pandemic-related challenges (e.g. difficulty obtaining tests, additional costs); change of practice to low-touch medication abortion care and provider perceptions of patient experience, including shifting demand, telemedicine acceptability and increased rural access. The second survey indicated uptake of telemedicine medication abortion among 89% of participants except in Quebec, where regulations meant procedures were nearly exclusively surgical. Restrictions did not delay care according to 76% of participants. Conclusions Canadian health care professionals report their facilities deemed abortion an essential service. Provinces and territories, except Quebec, described a robust pandemic transition to telemedicine to ensure access to services. Podcast An accompanying podcast is available in the Supplementary Data, in which the authors Dr Madeleine Ennis and Kate Wahl discuss their research on how family planning care and access to abortion services have changed during the COVID-19 pandemic. Lay Summary Access to abortion care was challenged by the response to COVID-19. Canada had fewer restrictions on medical abortion than many other countries when the pandemic began. The goal of this study was to describe the experiences of health care practitioners providing abortion in Canada and the impact of the pandemic and the pandemic response measures on abortion services. We conducted two surveys of physicians, nurse practitioners and administrators between July 2020 and January 2021. Most of the health care practitioners who participated reported that medical and surgical abortion care were essential and that, except in the province of Quebec, there was a rapid transition to virtual telemedicine care for first trimester abortions. Several practitioners said that virtual care made abortion more accessible. Other practitioners reported that it was challenging to order certain tests, access operating room facilities or make referrals for late second trimester cases. Practitioners felt that patients had strong fears about COVID-19 exposure and reported that limited contraception access was increasingly a reason for seeking abortion care. The results of the study suggested that abortion was considered essential and that the pandemic instigated a transition to virtual care in all provinces and territories except Quebec.

AbstractIn C. elegans, ectopic expression of the UNC-5 netrin receptor is sufficient to cause repulsion of growth cones and cells away from ventral sources of the UNC-6/netrin guidance cue. A genetic suppressor screen identified the seu-1 gene as required for repulsion of touch neuron growth cones ectopically expressing unc-5. We report here that seu-1 mutations also enhance the frequency of distal tip cell migrations of unc-5 or unc-40 mutants. The seu-1 gene encodes two novel proteins (SEU-1A and SEU-1B) containing a charged central domain and several regions of low amino acid complexity. Transgenic rescue experiments indicate that seu-1 can act cell autonomously in the touch neurons and distal tip cells and that SEU-1 function requires both the SEU-1A and SEU-1B isoforms. A GFP fusion construct was expressed in a dynamic pattern throughout development and localized in the nuclei of neuronal and non-neuronal cells, including gonadal leader cells. These results implicate nuclear SEU-1 in the interpretation of UNC-6/netrin directional information by migrating growth cones and cells.

Supplementary figures. (PDF 4815 kb)